1. Field of the Invention
This invention relates to a machine for stripping rubber, plastic or other flexible insulation from elongate electrical wire or cable, such as machines operated by electrical motors and utilizing a blade for cutting the insulation.
2. Description of Related Art Including Information Disclosed Under 37 CFR .sctn.1.97-1.99
Insulated electrical cable is used in many applications in home construction, and in commercial and industrial buildings. It is also used in great quantities in the utility area for the conducting of electricity for a variety of uses. Scrap electrical wire and cable can be recycled or reclaimed for the copper or other metals that are contained therein. Salvage yards generally pay a higher price for electrical wire and cable that has the insulation already stripped therefrom. Thus, prior attempts have been made to provide a machine that will strip the insulation off of electrical cable to facilitate the recycling of the metal insulated therein. One such machine for stripping insulation from cables is shown in U.S. Pat. No. 3,817,132 issued Jun. 18, 1974 to Emery, entitled "Machines For Stripping Insulation From Cables". This patent discloses a very complex machine with multiple moving parts designed to strip the insulation off of a cable. The patent shows a pair of circular cutters and a variety of gears and other moving parts. This machine is complex and expensive to manufacture.
Other machines have been used to strip the insulation off of a cable in sections to facilitate electrical connections. In U.S. Pat. No. 4,699,027 to Guyette issued Oct. 13, 1987 a cable stripping apparatus is illustrated to strip insulation off of cable ends to facilitate electrical connections. This cable stripping apparatus has numerous moving parts and is also expensive to manufacture. It appears to be designed for use in a factory or industrial setting where larger capital expenditures are more common. It is not usable for stripping elongate sections of insulation off of a cable.
U.S. Pat. No. 4,597,176 to Shields issued Jul. 1, 1986 entitled "Method For Removing Insulation From Flat Cable", illustrates a device for removing in sections insulation from a flat cable to allow the cable to be connected in selected lengths to terminals for making electrical connections. This machine can not remove elongate sections of insulation from electrical cable for the purpose of salvaging the metal insulated therein.
Other patents include U.S. Pat. No. 4,352,305 to Rodenbeck issued Oct. 5, 1982; U.S. Pat. No. 4,614,135 to Ito issued Sep. 30, 1986; U.S. Pat. No. 4,345,362 to deGivry issued Aug. 24, 1982; U.S. Pat. No. 4,187,745 to Lambert issued Feb. 12, 1980; and U.S. Pat. No. 4,584,912 to Gudmestad issued Apr. 29, 1986 all illustrating a variety of machines for stripping insulation off of electrical cable. All of these patents disclose complicated devices requiring many moving parts to accomplish the stripping of the insulation off the cable. Many of these patents relate to stripping insulation off of cable transversely to facilitate electrical connections and not to stripping insulation lengthwise off of the cable.
Thus, prior wiring stripping apparatus are relatively complicated devices with numerous moving parts. Further, they are expensive to manufacture making it difficult for the average electrician or small salvage yard to afford. Also, many do not appear to be easily portable so as to be useable in a variety of locations. Further they are not designed to strip insulation off of cable lengthwise.
Further problems are often encountered in removing insulation from different sized cables having different sizes of cores and different thicknesses of insulation. Not only do insulations differ in thickness and kind but also some insulations are more difficult to remove than others. Prior art machines are complex mechanisms utilizing complicated means for feeding a length of wire into the machine and for measuring wire length and thickness. They generally employ cams, levers, and switches to control the many operations of the machine. As a result, prior machines are expensive, complicated assemblies and are prone to malfunction. Further, many require a skilled operator to operate the machine.